In situ preparation of spindle calcium carbonate-chitosan/poly (vinyl alcohol) anti-biofouling hydrogels inspired by shellfish

Hydrogels have received intensive interest in the marine environment due to their excellent anti-biofouling properties. In this work, a series of spindle CaCO3-Chitosan/poly (vinyl alcohol) (SCC/PVA) hydrogels were in situ prepared inspired by the good mechanical self-cleaning and properties of seashell. The morphologies, structure and components of the prepared hydrogels were studied by SEM, FTIR spectra, XRD, TGA, and TEM. The anti-biofouling properties of the prepared hydrogels against protein, bacteria and algae were evaluated by ultrahigh-resolution fluorescence microscopy. Results indicated that chitosan can affect the growth process of CaCO3 leading to the formation of a hollow spindle structure of CaCO3. The prepared SCC/PVA hydrogels have excellent underwater superoleophobicity properties. SCC/PVA-3 hydrogel has the best superoleophobicity property with an underwater contact angle of 167.5°. The compressive strength of SCC/PVA-3 hydrogel is 25 MPa, which is attributed to the doping of SCC. Compared to PVA hydrogel, the settlement of the Navicula, Nitzschia Closterium on the surface of SCC/PVA-3 hydrogels sample decreased by approximately 94 % and 88 %, respectively. The SCC/PVA hydrogels have some antibacterial ability against E. coli. SCC/PVA-3 hydrogel can effectively inhibit the adhesion of elegans with a test time of 180 days in the South China Sea.